Vehicles particularly useful as vtol vehicles

ABSTRACT

A vehicle includes a fuselage, at least one lift-producing propeller carried by the fuselage on each side of its transverse axis a pilot&#39;s compartment formed in the fuselage between the lift-producing propellers and substantially aligned with the longitudinal axis, and a pair of payload bays formed in the fuselage between the lift-producing propellers and on opposite sides of the pilot&#39;s compartment. Many variations are described enabling the vehicle to be used not only as a VTOL vehicle, but also as a multi-function utility vehicle for performing many diverse functions including hovercraft and ATV functions.

FIELD AND BACKGROUND OF THE INVENTION

[0001] The present invention relates to vehicles, and particularly toVertical Take-Off and Landing (VTOL) vehicles having multi-functioncapabilities.

[0002] VTOL vehicles rely on direct thrust from propellers or rotors,directed downwardly, for obtaining lift necessary to support the vehiclein the air. Many different types of VTOL vehicles have been proposedwhere the weight of the vehicle in hover is carried directly by rotorsor propellers, with the axis of rotation perpendicular to the ground.One well known vehicle of this type is the conventional helicopter whichincludes a large rotor mounted above the vehicle fuselage. Other typesof vehicles rely on a multitude of propellers that are either exposed(e.g., unducted fans), or installed inside circular cavities, shrouds,ducts or other types of nacelle (e.g., ducted fans), where the flow ofair takes place inside ducts. Some VTOL vehicles (such as the V-22) usepropellers having their axes of rotation fully rotatable (up to 90degrees or so) with respect to the body of the vehicle; these vehiclesnormally have the propeller axis perpendicular to the ground forvertical takeoff and landing, and then tilt the propeller axis forwardfor normal flight. Other vehicles use propellers having nearlyhorizontal axes, but include aerodynamic deflectors installed behind thepropeller which deflect all or part of the flow downwardly to createdirect upward lift.

[0003] A number of VTOL vehicles have been proposed in the past wheretwo or four propellers, usually mounted inside ducts (i.e., ductedfans), were placed forwardly of, and rearwardly of, the main payload ofthe vehicle. One typical example is the Piasecki VZ-8 ‘Flying Jeep’which had two large ducts, with the pilots located to the sides of thevehicle, in the central area between the ducts. A similar configurationwas used on the Chrysler VZ-6 and on the CityHawk flying car. Also theBensen ‘Flying Bench’ uses a similar arrangement. The Curtiss WrightVZ-7 and the Moller Skycar use four, instead of two, thrusters where twoare located on each side (forward and rear) of the pilots and thepayload, the latter being of fixed nature at the center of the vehicle,close to the vehicle's center of gravity.

[0004] The foregoing existing vehicles are generally designed forspecific functions and are therefore not conveniently capable ofperforming a multiplicity of functions.

OBJECTS AND BRIEF SUMMARY OF THE INVENTION

[0005] An object of the present invention is to provide a vehicle of arelatively simple inexpensive construction and yet capable of performinga multiplicity of different functions.

[0006] According to the present invention, there is provided a vehicle,comprising: a fuselage having a longitudinal axis and a transverse axis;at least one lift-producing propeller carried by the fuselage on eachside of the transverse axis; a pilot's compartment formed in thefuselage between the lift-producing propellers and substantially alignedwith the longitudinal axis; and a pair of payload bays formed in thefuselage between the lift-producing propellers and on opposite sides ofthe pilot's compartment.

[0007] According to further features in the preferred embodiments of theinvention described below, each of the payload bays includes a coverdeployable to an open position providing access to the payload bay, andto a closed position covering the payload bay. In some describedpreferred embodiments, the cover of each of the payload bays ispivotally mounted to the fuselage along an axis parallel to thelongitudinal axis of the fuselage at the bottom of the respectivepayload bay, such that when the cover is pivoted to the open position italso serves as a support for supporting the payload or a part thereof inthe respective payload bay.

[0008] Various embodiments of the invention are described below, whereinthe lift propellers are ducted or unducted fans, and wherein thefuselage carries a pair of the lift producing propellers on each side ofthe transverse axis, a vertical stabilizer at the rear end of thefuselage, or a horizontal stabilizer at the rear end of the fuselage.

[0009] Several preferred embodiments are also described below whereinthe fuselage further carries a pair of pusher propellers at the rear endof the fuselage, on opposite sides of the longitudinal axis. In thedescribed embodiments, the fuselage carries two engines, each fordriving one of the lift-producing propellers and pusher propellers withthe two engines being mechanically coupled together in a commontransmission. In one described preferred embodiment, the two engines arelocated in engine compartments in pylons formed in the fuselage onopposite sides of its longitudinal axis. In another describedembodiment, the two engines are located in a common engine compartmentaligned with the longitudinal axis of the fuselage and underlying thepilot's compartment.

[0010] One preferred embodiment is described wherein the vehicle is avertical take-off and landing (VTOL) vehicle and includes a pair of stubwings each pivotally mounted under one of the payload bays to aretracted, stored position, and to an extended, deployed position forenhancing lift. Another embodiment is described wherein the vehicleincludes a flexible skirt extending below the fuselage enabling thevehicle to be used as, or converted to, a hovercraft for movement overground or water. A further embodiment is described wherein the vehicleincludes large wheels attachable to the rear end of the fuselage forconverting the vehicle to an all terrain vehicle (ATV).

[0011] As will be described more particularly below, a vehicleconstructed in accordance with the foregoing features may be of arelatively simple and inexpensive construction capable of convenientlyperforming a host of different functions besides the normal functions ofa VTOL vehicle. Thus, the foregoing features enable the vehicle to beconstructed as a utility vehicle for a large array of tasks includingserving as a weapons platform; transporting personnel, weapons, and/orcargo; evacuating medically wounded, etc., without requiring majorchanges in the basic structure of the vehicle when transferring from onetask to another.

[0012] Further features and advantages of the invention will be apparentfrom the description below.

BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The invention is herein described, by way of example only, withreference to the accompanying drawings, wherein:

[0014]FIG. 1 illustrates one form of VTOL vehicle constructed inaccordance with present invention with two ducted fans;

[0015]FIG. 2 illustrates an alternative construction with four ductedfans;

[0016]FIG. 3 illustrates a construction similar to FIG. 1 with freepropellers, i.e., unducted fans;

[0017]FIG. 4 illustrates a construction similar to FIG. 2 with freepropellers;

[0018]FIG. 5 illustrates a construction similar to that of FIG. 1 butincluding two propellers, instead of a single propeller, mountedside-by-side in a single, oval shaped duct at each end of the vehicle;

[0019]FIGS. 6a, 6 b and 6 c are side, top and rear views, respectively,illustrating another VTOL vehicle constructed in accordance with thepresent invention and including pusher propellers in addition to thelift-producing propellers;

[0020]FIG. 7 is a diagram illustrating the drive system in the vehicleof FIGS. 6a-6 c;

[0021]FIG. 8 is a pictorial illustration of a vehicle constructed inaccordance with FIGS. 6a-6 c and 7;

[0022]FIG. 8a-8 d illustrate examples of various tasks and missionscapable of being accomplished by the vehicle of FIG. 8;

[0023]FIGS. 9a and 9 b are side and top views, respectively,illustrating another VTOL vehicle constructed in accordance with thepresent invention;

[0024]FIG. 10 is a diagram illustrating the drive system in the vehicleof FIGS. 9a and 9 b;

[0025]FIGS. 11a and 11 b are side and top views, respectively,illustrating a VTOL vehicle constructed in accordance with any one ofFIGS. 6a-10 but equipped with deployable stub wings, the wings beingshown in these figures in their retracted stowed positions;

[0026]FIG. 11c and 11 d are views corresponding to those of FIGS. 11aand 11 b but showing the stub wings in their deployed, extendedpositions;

[0027]FIG. 12 is a perspective rear view of a vehicle constructed inaccordance with any one of FIGS. 6a-10 but equipped with a lower skirtfor converting the vehicle to a hovercraft for movement over ground orwater; and

[0028]FIG. 13 is a perspective rear view of a vehicle constructed inaccordance with any one of FIGS. 6a-10 but equipped with large wheelsfor converting the vehicle for ATV (all terrain vehicle) operation.

[0029] It is to be understood that the foregoing drawings, and thedescription below, are provided primarily for purposes of facilitatingunderstanding the conceptual aspects of the invention and variouspossible embodiments thereof, including what is presently considered tobe a preferred embodiment. In the interest of clarity and brevity, noattempt is made to provide more details than necessary to enable oneskilled in the art, using routine skill and design, to understand andpractice the described invention. It is to be further understood thatthe embodiments described are for purposes of example only, and that theinvention is capable of being embodied in other forms and applicationsthan described herein.

DESCRIPTION OF PREFERRED EMBODIMENTS

[0030] As indicated earlier, the present invention provides a vehicle ofa novel construction which permits it to be used for a large variety oftasks and missions with no changes, or minimum changes, required whenconverting from one mission to another.

[0031] The basic construction of such a vehicle is illustrated in FIG.1, and is therein generally designated 10. It includes a fuselage 11having a longitudinal axis LA and a transverse axis TA. Vehicle 10further includes two lift-producing propellers 12 a, 12 b carried at theopposite ends of the fuselage 11 along its longitudinal axis LA and onopposite sides of its transverse axis TA. Lift-producing propellers 12a, 12 b are ducted fan propulsion units extending vertically through thefuselage and rotatable about vertical axes to propel the air downwardlyand thereby to produce an upward lift.

[0032] Vehicle 10 further includes a pilot's compartment 13 formed inthe fuselage 11 between the lift-producing propellers 12 a, 12 andsubstantially aligned with the longitudinal axis LA and transverse axisTA of the fuselage. The pilot's compartment 13 may be dimensioned so asto accommodate a single pilot or two (or more) pilots, as shown, forexample, in FIG. 6a.

[0033] Vehicle 10 illustrated in FIG. 1 further includes a pair ofpayload bays 14 a, 14 b formed in the fuselage 11 laterally on theopposite sides of the pilot's compartment 13 and between thelift-producing propellers 12 a, 12 b. The payload bays 14 a, 14 b shownin FIG. 1 are substantially flush with the fuselage 11, as will bedescribed more particularly below with respect to FIGS. 6a-6 c and thepictorial illustration in FIGS. 8a-8 d. Also described below,particularly with respect to the pictorial illustrations of FIGS. 8a-8d, are the wide variety of tasks and missions capable of beingaccomplished by the vehicle when constructed as illustrated in FIG. 1(and in the later illustrations), and particularly when provided withthe payload bays corresponding to 14 a, 14 b of FIG. 1.

[0034] Vehicle 10 illustrated in FIG. 1 further includes a front landinggear 15 a and a rear landing gear 15 b mounted at the opposite ends ofits fuselage 11. In FIG. 1 the landing gears are non-retractable, butcould be retractable as in later described embodiments. Aerodynamicstabilizing surfaces may also be provided, if desired, as shown by thevertical stabilizers 16 a, 16 b carried at the rear end of fuselage 11on the opposite sides of its longitudinal axis LA.

[0035]FIG. 2 illustrates another vehicle construction in accordance withthe present invention. In the vehicle of FIG. 2, therein generallydesignated 20, the fuselage 21 is provided with a pair of lift-producingpropellers on each side of the transverse axis of the fuselage. Thus, asshown in FIG. 2, the vehicle includes a pair of lift-producingpropellers 22 a, 22 b at the front end of the fuselage 21, and anotherpair of lift-producing propellers 22 c, 22 d at the rear end of thefuselage. The lift-producing propellers 22 a-22 d shown in FIG. 2 arealso ducted fan propulsion units. However, instead of being formed inthe fuselage 21, they are mounted on mounting structures 21 a-21 d toproject laterally of the fuselage.

[0036] Vehicle 20 illustrated in FIG. 2 also includes the pilot'scompartment 23 formed in the fuselage 21 between the two pairs oflift-producing propellers 22 a, 22 b and 22 c, 22 d, respectively. As inthe case of the pilot's compartment 13 in FIG. 1, the pilot'scompartment 23 in FIG. 2 is also substantially aligned with thelongitudinal axis LA and transverse axis TA of the fuselage 21.

[0037] Vehicle 20 illustrated in FIG. 2 further includes a pair ofpayload bays 24 a, 24 b formed in the fuselage 21 laterally of thepilot's compartment 23 and between the two pairs of lift-producingpropellers 22 a-22 d. In FIG. 2, however, the payload bays are notformed integral with the fuselage, as in FIG. 1, but rather are attachedto the fuselage so as to project laterally on opposite sides of thefuselage. Thus, payload bay 24 a is substantially aligned with thelift-producing propellers 22 a, 22 c on that side of the fuselage; andpayload bay 24 b is substantially aligned with the lift-producingpropellers 22 b and 22 d at that side of the fuselage.

[0038] Vehicle 20 illustrated in FIG. 2 also includes a front landinggear 25 a and a rear landing gear 25 b, but only a single verticalstabilizer 26 at the rear end of the fuselage aligned with itslongitudinal axis. It will be appreciated however, that vehicle 20illustrated in FIG. 2 could also include a pair of vertical stabilizers,as shown at 16 a and 16 b in FIG. 1, or could be constructed without anysuch aerodynamic stabilizing surface.

[0039]FIG. 3 illustrates a vehicle 30 also including a fuselage 31 of avery simple construction having a forward mounting structure 31 a formounting the forward lift-producing propeller 32 a, and a rear mountingstructure 31 b for mounting the rear lift-producing propeller 32 b. Bothpropellers are unducted, i.e., free, propellers. Fuselage 31 is formedcentrally thereof with a pilots compartment 33 and carries the twopayload bays 34 a, 34 b on its opposite sides laterally of the pilot'scompartment.

[0040] Vehicle 30 illustrated in FIG. 3 also includes a front landinggear 35 a and a rear landing gear 35 b, but for simplification purposes,it does not include an aerodynamic stabilizing surface corresponding tovertical stabilizers 16 a, 16 b in FIG. 1.

[0041]FIG. 4 illustrates a vehicle, generally designated 40, of asimilar construction as in FIG. 2 but including a fuselage 41 mounting apair of unducted propellers 42 a, 42 b at its front end, and a pair ofunducted propellers 42 c, 42 d at its rear end by means of mountingstructures 41 a-41 d, respectively. Vehicle 40 further includes apilot's compartment 43 centrally of the fuselage, a pair of payload bays44 a, 44 b laterally of the pilot's compartment, a front landing gear 45a, a rear landing gear 45 b, and a vertical stabilizer 46 at the rearend of the fuselage 41 in alignment with its longitudinal axis.

[0042]FIG. 5 illustrates a vehicle, generally designated 50, including afuselage 51 mounting a pair of lift-producing propellers 52 a, 52 b atits front end, and another pair 52 c, 52 d at its rear end. Each pair oflift-producing propellers 52 a, 52 b and 52 c, 52 d is enclosed within acommon oval-shaped duct 52 e, 52 f at the respective end of thefuselage.

[0043] Vehicle 50 illustrated in FIG. 5 further includes a pilot'compartment 53 formed centrally of the fuselage 51, a pair of payloadbays 54 a, 54 b laterally of the pilot's compartment 53, a front landinggear 55 a, a rear landing gear 55 b, and vertical stabilizers 56 a, 56 bcarried at the rear end of the fuselage 51.

[0044]FIGS. 6a, 6 b and 6 c are side, top and rear views, respectively,of another vehicle constructed in accordance with the present invention.The vehicle illustrated in FIGS. 6a-6 c, therein generally designated60, also includes a fuselage 61 mounting a lift-producing propeller 62a, 62 b at its front and rear ends, respectively. The latter propellersare preferably ducted units as in FIG. 1.

[0045] Vehicle 60 further includes a pilot's compartment 63 centrally ofthe fuselage 61, a pair of payload bays 64 a, 64 b laterally of thefuselage and of the pilot's compartment, a front landing gear 65 a, arear landing gear 65 b, and a stabilizer, which, in this case, is ahorizontal stabilizer 66 extending across the rear end of the fuselage61.

[0046] Vehicle 60 illustrated in FIGS. 6a-6 c further includes a pair ofpusher propellers 67 a, 67 b, mounted at the rear end of the fuselage 61at the opposite ends of the horizontal stabilizer 66. As shownparticularly in FIGS. 6c the rear end of the fuselage 61 is formed witha pair of pylons 61 a, 61 b, for mounting the two pusher propellers 67a, 67 b, together with the horizontal stabilizer 66.

[0047] The two pusher propellers 67 a, 67 b are preferablyvariable-pitch propellers enabling the vehicle to attain higherhorizontal speeds. The horizontal stabilizer 66 is used to trim thevehicle's pitching moment caused by the ducted fans 62 a, 62 b, therebyenabling the vehicle to remain horizontal during high speed flight.

[0048] Each of the pusher propellers 67 a, 67 b is driven by an engineenclosed within the respective pylon 61 a, 61 b. The two engines arepreferably turbo-shaft engines. Each pylon is thus formed with an airinlet 68 a, 68 b at the forward end of the respective pylon, and with anair outlet (not shown ) at the rear end of the respective pylon.

[0049]FIG. 7 schematically illustrates the drive within the vehicle 60for driving the two ducted fans 62 a, 62 b (only the top of the gearboxof each ducted fan being shown), as well as the pusher propellers 67 a,67 b. The drive system, generally designated 70, includes two engines71, 71 b, each incorporated in an engine compartment within one of thetwo pylons 61 a, 61 b. Each engine 71 a, 71 b, is coupled by anover-running clutch 72 a, 72 b, to a gear box 73 a, 73 b coupled on oneside to the respective thrust propeller 67 a, 67 b, and on the oppositeside to a transmission for coupling to the two ducted fans 62 a, 62 b atthe opposite ends of the fuselage. Thus, as schematically shown in FIG.7, the latter transmission includes additional gear boxes 74 a, 74 bcoupled to rear gear box 75 b for driving the rear ducted fan 62 b, andfront gear box 75 a for driving the front ducted fan 62 b.

[0050]FIG. 8 pictorially illustrates an example of the outer appearancethat vehicle 60 may take.

[0051] In the pictorial illustration of FIG. 8, those parts of thevehicle which correspond to the above-described parts in FIGS. 6a-6 care identified by the same reference numerals in order to facilitateunderstanding. FIG. 8, however, illustrates a number of additionalfeatures which may be provided in such a vehicle.

[0052] Thus, as shown in FIG. 8, the front end of the fuselage 61 may beprovided with a stabilized sight and FLIR (Forward Looking Infra-Red)unit, as shown at 81, and with a gun at the forward end of each payloadbay, as shown at 82. In addition, each payload bay may include a cover83 deployable to an open position providing access to the payload bay,and to a closed position covering the payload bay with respect to thefuselage 61.

[0053] In FIG. 8, cover 83 of each payload bay is pivotally mounted tothe fuselage 61 along an axis 84 parallel to the longitudinal axis ofthe fuselage at the bottom of the respective bay. The cover 83, when inits closed condition, conforms to the outer surface of the fuselage 61and is flush therewith. When the cover 83 is pivoted to its openposition, it serves as a support for supporting the payload, or a partthereof, in the respective payload bay.

[0054] The latter feature is more particularly shown in FIGS. 8a-8 dwhich illustrate various task capabilities of the vehicle asparticularly enabled by the pivotal covers 83 for the two payload bays.Thus, FIG. 8a illustrates the payload bays used for mounting ortransporting guns or ammunition 85 a; FIG. 8b illustrates the use of thepayload bays for transporting personnel or troops 85 b; FIG. 8cillustrates the use of the payload bays for transporting cargo 85 c; andFIG. 8d illustrates the use of the payload bays for evacuating wounded85 d. Many other task or mission capabilities will be apparent.

[0055]FIGS. 9a and 9 b are side and top views, respectively,illustrating another vehicle, generally designated 90, of a slightlymodified construction from vehicle 60 described above. Thus, vehicle 90illustrated in FIGS. 9a and 9 b also includes a fuselage 91, a pair ofducted-fan type lift-producing propellers 92 a, 92 b at the oppositeends of the fuselage, a pilot's compartment 93 centrally of thefuselage, and a pair of payload bays 94 a, 94 b laterally of the pilot'scompartment 93. Vehicle 90 further includes a front landing gear 95 a, arear landing gear 95 b, a horizontal stabilizer 96, and a pair of pusherpropellers 97 a, 97 b, at the rear end of fuselage 91.

[0056]FIG. 10 schematically illustrates the drive system in vehicle 90.Thus as shown in FIG. 10, vehicle 90 also includes two engines 101 a,101 b for driving the two ducted fans 92 a, 92 b and the two pusherpropellers 97 a, 97 b, respectively, as in vehicle 60. However, whereasin vehicle 60 the two engines are located in separate enginecompartments in the two pylons 61 a, 61 b, in vehicle 90 illustrated inFIGS. 9a and 9 b both engines are incorporated in a common enginecompartment, schematically shown at 100 in FIG. 9a, underlying thepilot's compartment 93. The two engines 101 a, 101 b (FIG. 10), may alsobe turbo-shaft engines as in FIG. 7. For this purpose, the centralportion of the fuselage 91 is formed with a pair of air inlet openings98 a, 98 b forward of the pilot's compartment 93, and with a pair of airoutlet openings 99 a, 99 b rearwardly of the pilot's compartment.

[0057] As shown in FIG. 10, the two engines 101 a, 101 b drive, via theover-running clutches 102 a, 102 b, a pair of hydraulic pumps 103 a, 103b which, in turn, drive the drives 104 a, 104 b of the two pusherpropellers 97 a, 97 b. The two engines 101 a, 101 b are further coupledto a drive shaft 105 which drives the drives 106 a, 106 b of the twoducted fans 92 a, 92 b, respectively.

[0058]FIGS. 11a-11 d illustrate another vehicle, therein generallydesignated 110, which is basically of the same construction as vehicle60 described above with respect to FIGS. 6a-6 c, 7, 8 and 8 a-8 d; tofacilitate understanding, corresponding elements are thereforeidentified by the same reference numerals. Vehicle 110 illustrated inFIGS. 11a-11 d, however, is equipped with two stub wings, generallydesignated 111 a, 111 b, each pivotally mounted to the fuselage 61,under one of the payload bays 64 a, 64 b, to a retracted position shownin FIGS. 11a and 11 b, or to an extended deployed position shown inFIGS. 11c and 11 d for enhancing the lift produced by the ducted fans 62a, 62 b. Each of the stub wings 111 a, 111 b is actuated by an actuator112 a, 112 b driven by a hydraulic or electrical motor (not shown).Thus, at low speed flight, the stub wings 111 a, 111 b, would be pivotedto their stowed positions as shown in FIGS. 11a and 11 b; but at highspeed flight, they could be pivoted to their extended or deployedpositions, as shown in FIGS. 11c and 11 d, to enhance the lift producedby the ducted fans 61 a, 61 b. Consequently, the blades in the ductedfans would be at low pitch producing only a part of the total liftforce.

[0059] The front and rear landing gear, shown at 115 a and 115 b, couldalso by pivoted to a stowed position to enable higher speed flight, asshown in FIGS. 11c and 11 d. In such case, the front end of the fuselage61 would preferably be enlarged to accommodate the landing gear when inits retracted condition. Vehicle 110 illustrated in FIGS. 11a-11 d mayalso include ailerons, as shown at 116 a, 116 b (FIG. 11d) for rollcontrol.

[0060]FIG. 12 illustrates how the vehicle, such as vehicle 60illustrated in FIGS. 6a-6 d, may be converted to a hovercraft fortravelling over ground or water. Thus, the vehicle illustrated in FIG.12, and therein generally designated 120, is basically of the sameconstruction as described above with respect to FIGS. 6a-6 d, andtherefore corresponding parts have been identified with the samereference numerals. In vehicle 120 illustrated in FIG. 12, however, thelanding gear wheels (65 a, 65 b, FIGS. 6a-6 d) have been removed,folded, or otherwise stowed, and instead, a skirt 121 has been appliedaround the lower end of the fuselage 61. The ducted fans 62 a, 62 b, maybe operated at very low power to create enough pressure to cause thevehicle to hover over the ground or water as in hovercraft vehicles. Thevariable pitch pusher propellers 67 a, 67 b would provide forward orrear movement, as well as steering control, by individually varying thepitch, as desired, of each propeller.

[0061] Vehicles constructed in accordance with the present invention mayalso be used for movement on the ground. Thus, the front and rear wheelsof the landing gears can be driven by electric or hydraulic motorsincluded within the vehicle.

[0062]FIG. 13 illustrates how such a vehicle can also be used as an ATV(all terrain vehicle). The vehicle illustrated in FIG. 13, thereingenerally designated 130, is basically of the same construction asvehicle 60 illustrated in FIGS. 6a-6 d, and therefore correspondingparts have been identified by the same reference numerals to facilitateunderstanding. In vehicle 130 illustrated in FIG. 13, however, the tworear wheels of the vehicle are replaced by two (or four) larger ones,bringing the total number of wheels per vehicle to four (or six). Thus,as shown in FIG. 13, the front wheels (e.g., 65 a, FIG. 6c) of the frontlanding gear are retained, but the rear wheels are replaced by twolarger wheels 135 a (or by an additional pair of wheels, not shown), toenable the vehicle to traverse all types of terrain.

[0063] When the vehicle is used as an ATV as shown in FIG. 13, the frontwheels 65 a or rear wheels would provide steering, while the pusherpropellers 67 a, 67 b and main lift fans 62 a, 62 b would bedisconnected but could still be powered-up for take-off if so desired.

[0064] It will thus be seen that the invention thus provides a utilityvehicle of a relatively simple structure which is capable of performinga wide variety of VTOL functions, as well as many other tasks andmissions, with minimum changes in the vehicle to convert it from onetask or mission to another.

[0065] While the invention has been described with respect to severalpreferred embodiments, it will be appreciated that these are set forthmerely for purposes of example, and that many other variations,modifications and applications of the invention will be apparent.

What is claimed is:
 1. A vehicle, comprising: a fuselage having alongitudinal axis and a transverse axis; at least one lift-producingpropeller carried by said fuselage on each side of said transverse axis;a pilot's compartment formed in said fuselage between saidlift-producing propellers and substantially aligned with saidlongitudinal axis; and a pair of payload bays formed in said fuselagebetween said lift-producing propellers and on opposite sides of saidpilot's compartment.
 2. The vehicle according to claim 1, wherein eachof said payload bays includes a cover deployable to an open positionproviding access to said payload bay, and to a closed position coveringthe payload bay.
 3. The vehicle according to claim 2, wherein the coverof each of said payload bays is pivotally mounted to the fuselage alongan axis parallel to said longitudinal axis of the fuselage at the bottomof the respective payload bay, such that when the cover is pivoted tosaid open position it serves as a support for supporting the payload ora part thereof in the respective payload bay.
 4. The vehicle accordingto claim 1, wherein said lift-producing propellers are ducted fans. 5.The vehicle according to claim 1, wherein said lift-producing propellersare unducted fans.
 6. The vehicle according to claim 1, wherein saidfuselage carries a pair of said lift-producing propellers on each sideof said transverse axis.
 7. The vehicle according to claim 1, whereinsaid fuselage further carries a vertical stabilizer at the rear end ofthe fuselage.
 8. The vehicle according to claim 1, wherein said fuselagefurther carries a horizontal stabilizer at the rear end of the fuselage.9. The vehicle according to claim 1, wherein said fuselage furthercarries a pair of pusher propellers at the rear end of the fuselage onopposite sides of said longitudinal axis.
 10. The vehicle according toclaim 9, wherein said fuselage carries two engines, each for driving oneof said lift-producing propellers and pusher propellers; said twoengines being mechanically coupled together in a common transmission.11. The vehicle according to claim 10, wherein said two engines arelocated in engine compartments in pylons formed in said fuselage onopposite sides of said longitudinal axis.
 12. The vehicle according toclaim 8, wherein said two engines are located in a common enginecompartment aligned with said longitudinal axis and underlying saidpilot's compartment.
 13. The vehicle according to claim 1, wherein thevehicle is a vertical take-off and landing (VTOL) vehicle.
 14. Thevehicle according to claim 13, wherein said VTOL vehicle includes a pairof stub wings each pivotally mounted under one of said payload bays to aretracted, stored position, and to an extended, deployed position forenhancing lift.
 15. The vehicle according to claim 1, wherein thevehicle includes a flexible skirt extending below the fuselage enablingthe vehicle to be used as a hovercraft for movement over ground orwater.
 16. The vehicle according to claim 15, wherein said fuselagecarries a pair of pusher propellers at the rear end of the fuselage onopposite sides of its longitudinal axis.
 17. The vehicle according toclaim 1, wherein the vehicle includes large wheels attachable to therear end of the fuselage for converting the vehicle to an all terrainvehicle (ATV).